"Others there are, who, trimm'd in forms and visages of duty, Keep yet their hearts attending on themselves, And throwing but shows of service on their lords Do well thrive by them; and when they have lined their coats, Do themselves homage. These fellows have some soul, And such a one do I profess myself. For, sir, It is as sure as you are Roderigo, Were I the Moor, I would not be Iago.In following him, I follow but myself; Heaven is my judge, not I for love and duty, But seeming so, for my peculiar end. For when my outward action doth demonstrate The native act and figure of my heartIn complementextern, 'tis not long after But I will wear my heart upon my sleeve For dawsto peck at: I am not what I am.

"Knavery's plain face is never seen till used."

"How am I then a villainTo counsel Cassio to this parallel course,Directly to his good? Divinity of hell!When devils will the blackest sins put on,They do suggest at first with heavenly shows."

Iago (Boo! Hiss!) the master of disguised villany, explains why being open and honest is for fools and that treachery is the best policy.